In an air-conditioning apparatus, refrigerant having heat is circulated through a pipe provided between an outdoor unit and an indoor unit, thereby generating conditioned air. In an air-conditioning apparatus capable of simultaneously performing cooling and heating, a relay unit is provided between an outdoor unit and indoor units, and distributes refrigerant to the indoor units.
In the case where refrigerant flows through a pipe in the relay unit, when the surface temperature of the pipe becomes lower than or equal to a dew-point temperature, dew-condensation water generates on the surface of the pipe, and water collects on the bottom of the relay unit.
Patent Literature 1 discloses an example of a method for draining dew-condensation water generated in an indoor unit. Patent Literature 1 discloses that a drain pan which receives dew-condensation water is provided at the indoor unit, a drain port is provided in the drain pan, and a drain hose is connected to the drain port, to thereby drain drainage water to the outside of a building.